Condenser-cleaning system



March 10, 1931. SCHMIDT 1,795,348

CONDENS ER CLEANING SYSTEM Filed March 30, 1927 I N VEN TOR.

".ESchmidi' BY @AM A TTORNEYS.

Patented Mar. 10, 1931 l Tsr osrics HENRY F. SCHMIDT, OF LANTSDOWNE, PENNSYLVANIA, ASSIGNQR 'TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A GORPORATION O F PENNSYLVANIA CONDENSER-CLEANING SYSTEM Application filed March so, 1927. Serial No. 179,596.

My invention relates to systems for cleaning tubular heat exchan ers, and particular' 1y to systems for continuously cleaning the tubular members of this class of equipment.

Tubular heat exchangers such, for exam ple, as those employed in power plants, are often subjected to conditions of service which are unfavorable to obtain good efhciency of operation; and, consequently, the conditions under which a heat exchanger is to be expected to render satisfactory service, and also the intended mannerof operating the plant, the frequencywith which units may be taken out of service for'repairs, and the like, are some of the circumstances of which cognizance must be taken in installations of this classof equipment.

For example, conditions may be such that circulating media for the various heat, exchangers mu st be supplied from water containing city refuse, debris, or other foreign matter which will accumulate more or less gradually, depending upon, the particul'ar conditions, in the form of a deposit in the tubes of a heat exchanger, and, thus, serve to retard circulation and to interfere with the transfer of heat through the walls of the tubes.

Such conditions may be overcome, either by frequent cleaning of the tubes, or by installing units of such large capacity that they will be able to perform the required service even after a considerable amount of foreign matter has accumulated in their tubes, thus obviating the. necessity for frequent cleaning. The latter procedure is undesirable for the reason that the larger units cost more, and also for the reason that these larger units require more space, which may be ata premium. Furthermore, more power'is required to circulate fluid through tubes incrusted with foreign matter, than through clean tubes.

An object of my invention, therefore, is to so improve the art of operating tubular heat exchangers that the accumulation of foreign matter in the tubes may be avoided.

Another object is to provide a simple and efficient means for cleaning tubes, and for constantly maintaining the tubes of tubular 50 heat exchangers in a clean condition.

Other and further objects will appear as the description proceeds.

Apparatus embodying the features of my invention is shown in the accompanying drawings, in Which:

Fig. 1 is a view partly in elevation and partly in section of a surface condenser equipped with apparatus embodying my invention.' p c Fig. 2 is an elevation of a modified form of' separating means. i

.According to my invention, small hard objects, such as balls, or the like are continually passed through the tubes of a heat exchanger and, in this way, the accumulation of any appreciable amount offoreign matter in the tubes is effectively prevented. iMeansare provided for delivering the hard objects to the tubes through the circulating media, for collecting the hard objects after they have issuedfrom'the tubes, and for again introducing these same objects into the tubes.f.

A large class oftubular heat exchangers takethe form of surface condensers; and, in the drawing, I show a surface condenser, indicated generally at 10, equipped withapp'aratus embodying my invention. The surface condenser is of the usual formand com- 80 prises a shell 11, having-a steam inlet 12, a hotwell 13-, and a nest of tubes 14.

Suitable water box connections, such as at 15 and 16, are also provided. A circulating pump 17, having an inlet 18 and a discharge flow through a certain region or zone, such lie chamber 23 and the intake conduit. ln us form shown, such means includes the connections 28 and 29 of the ro ary pump, indicated generally at 31. Sun ale valves may connections 28 anc 29, respectively, of the pump 31, and the intake conduit 21 and the chamber 23, as for example, valves and 33, which are provided rel" for the purpose of facilitating the removal of the pump, should this be desired.

eroosed between the inlet and discharge 111?; the removal of this chamber, and for otne reasons which will appear later.

In the operation of the arrangement shown in Fig. 1, circulating media, such as cooling water, is supplied to the pump 17, thr ugh the intake 13, and is translated through the intake conduit into the water boX 15, through the tubes 14, from whence it issues into the water box 16, and is discharged through the conduit 22.

Small hard objects, such as balls 3?", of a size which will permit them to pass through the tubes, but not through the openings in screen 24 in chamber 23, are introduced into the circulating system, and are forced through the tubes 14 by the pressure of the circulating fluid. On issuing from the tubes, the hard objects 37 are caught by the screen 24, and due to the fact that this screen is disposed at an angle, these objects are directed to the connection 26, from whence they are removed, due to the operation of pump 31, which serves to establish a flow from chamber 23, to the intake conduit 21.

The hard objects pass through the pump 31, and are introduced, or injected into circulating media in conduit 21, and are, therefore, returned to the water boX 15, and again pass through the tubes in the manner just described. This operation may either be continuous, or it may .be continued for such periods of time as the conditions may require.

In Fig. 2, I show a modified form of means for separating the hard objects 37 from fluid discharged from the condenser. This separating means is in the form of a centrifugal separator, indicated generally at 41, and provided with an inlet 42, which is adapted to be connected to the discharge water box 16. This separator is also provided with a centrally disposed outlet 43, which is adapted to be connected to the conduit 22.

The respective inlet and discharge connections are so disposed, with respect to the cylindrical chamber 44 of the separating means, that fluid entering the inlet 42, is given a whirling action before it is discharged through the outlet 43. Disposed about the wall of the circular chamber 44, at any suitable point, is an outlet connection 46 of a somewhat smaller diameter than that of the conduit 22.

By means of an elbow, or the like 47, the connection 46 is adapted to be connected with the intake conduit 21, through the valves 32 and 33, and the pumping means 31. The hard objects, on entering the inlet 42 of this separating means, being heavier than the circulating medium, travel around the walls of chamber 44 and drop through connection 46, while the remainder of the circulating fluid passes out through discharge connection 43.

In the forms of my invention shown in both Figs. 1 and 2, the pumping means 31 is preferably operated in synchronism with the main circulating pump 17, so as to permit the streams of fluid to be combined with the minimum of shock.

In other respects, the operation of my invention with the separating means 41 is the same as that described in connection with the arrangement shown in Fig. 1.

l/Vhile I have shown a suitable fluid translating means such as a rotary pump 31 disposed in the connection between the intake and discharge conduits, it will be obvious that this pumping means may be omitted and that by carefully adjusting valve 36 in a discharge conduit, a suitable throttling action may be produced which will establish a flow from the chamber 23 to the intake conduit 21.

While I have shown my invention in but two forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

- What I claim is 1. The combination with a tubular heat exchanger having aplurality of heat transfer tubes, of a system for circulating liquid media through the tubes, means for introducing hard objects into the liquid media circulating through the tubes for cleansing the latter, a screen for collecting the hard objects and means for passing all the liquid media leaving the system through said screen.

2. The combination with a tubular heat exchanger and a circulating'fluid intake and a circulating fluid discharge conduit therefor, of means forcirculating fluid containing hard objects through the heat exchanger from the intake to the discharge conduit, means for collecting the hard objects in a zone in the discharge conduit, means providing a passage between the collecting zone and the intake conduit, and means for directing the hard objects into said passage. 7

3. The combination with a tubular heat exchanger and a circulating fluid intake and a circulating fluid discharge conduit therefor, of means for circulating fluid containing hard objects through the heat exchanger from the intake to the discharge conduit, means for collecting the hard objects in a zone in the discharge conduit, means providing a passage between the collecting zone and the intake conduit, means for directing the hard objects into said passage, and fluid translating means for causing fluid to flow through said passage from the collecting zone to the intake conduit.

4:. The combination with a tubular heat exchanger and a circulating fluid intake and a circulating fluid discharge conduit therefor, of means for circulating fluid containing hard objects through the heat exchanger from the intake conduit to the discharge conduit, means for collecting the hard objects in a zone in the discharge conduit, said collecting means being so formed as to decrease the velocity of flow of the circulating fluid in the collecting zone, means providing a passage between the collecting zone and the intake conduit, and means for directing the hard objects from the collecting zone to said passage.

5. The combination with a tubular heat cxchanger and a circulating fluid intake and a circulating fluid discharge conduit therefor, of means for circulating fluid containing hard objects through the heat exchanger from the intake conduit to the discharge conduit, means for collecting the hard objects in a zone in the discharge conduit, said collecting means being so formed as to decrease the velocity of flow of the fluid in the collecting zone, means providing a passage between the collecting zone andthe intake conduit, and means for causing fluid to flow through said passage from the collecting zone to the intake conduit.

6. The combination with a tubular heat exchanger having inlet and outlet conduits providing an open-circuit passage for circulating water, of means for introducing tubecleaning objects into the entering stream of the inlet conduit and a screen extending across the outlet conduit for separating such objects from the entire leaving stream of the outlet conduit.

7. The combination with a tubular heat exchanger having inlet and outlet conduits providing an open-circuit passage for circulating water, of means for lntroducing tube-cleaning objects into the entering stream of the in- 

